1. Technical Field
The present invention relates to a liquid ejecting head and a liquid ejecting apparatus.
2. Related Art
Some of ink jet type recording heads, which are one type of liquid ejecting heads, each include an actuator unit and a passage unit. The actuator unit is provided with piezoelectric elements and pressure-generating chambers. The passage unit includes a nozzle plate provided with nozzle openings communicating to the pressure-generating chambers and discharging ink droplets, and includes a reservoir-forming substrate provided with a reservoir serving as an ink chamber that is common to the pressure-generating chambers (for example, see pages 6 to 8 and FIGS. 1 and 2 in JP-A-2004-042559).
In such an ink jet type recording head, bubbles that occur or flow in liquid passages (in particular, the pressure-generating chambers) cause printing defects. Therefore, a maintenance action includes a cleaning step for eliminating bubbles. However, since the bubbles are not completely eliminated by the cleaning, there occurs a problem in which the printing characteristics are prevented from recovering due to the remaining bubbles. In particular, bubbles in the pressure-generating chambers are required to be surely eliminated. However, since the adhesive bonding substrates and being exposed to side walls of the pressure-generating chambers is low in affinity with ink, bubbles are apt to adhere to the adhesive, and cleaning at a low flow rate cannot readily eliminate the adhering bubbles.
In order to solve the above-mentioned problem, it is conceivable to use an acrylic resin-based adhesive having high affinity with ink. But the adhesive property of the acrylic resin-based adhesive is too low to be used for constituting an ink jet type recording head. It is also conceivable to increase the affinity of ink itself, but ink has a problem in which the flexibility in design is low.
Furthermore, these problems are present not only in ink jet type recording heads but also in liquid ejecting heads ejecting liquids other than ink.